The Nagaland Police on Saturday said that the investigation into the killing of 14 persons in Mon district last year revealed that the Army did not follow the Standard Operating Procedure and the rules of engagement for such an operation.

On the evening of December 4, the Army’s 21 Para Special Force had opened fire at a pick-up van carrying coal miners from Tiru to Oting village in Mon district, killing six on board. They had apparently mistaken the group of workers for insurgents. A crowd of protestors then set fire to vehicles belonging to the Army. The soldiers opened fire again, killing seven more civilians.

The violence spilled over into the afternoon of December 5 after locals entered a camp of the Assam Rifles in the district headquarters of Mon. At least one more person was killed after security forces fired back at the protestors.

In a statement on Saturday, the police said that “indiscriminate and disproportionate firing” led to the immediate death of six civilians and caused grievous injuries to two more.

Thirty members of the operations team of 21 Para Special Force, including one Army officer, have been named by the police in its chargesheet in the case.

At a press conference, Director General of Police, Nagaland, T John Longkumer said that they sought permission from the Centre’s Department of Military Affairs in the first week of April to take action against the soldiers named in the chargesheet. A reminder letter was sent in May, he added.

The director general of police said the chargesheet was submitted to the District and Sessions Court in Mon on May 30.

A first information report filed by the Nagaland Police in December had said that the Army’s 21 Para Special Force “blankly opened fire” with the “intention to murder and injure civilians”.

The Army started a Court of Inquiry to look into the killings, while the Nagaland government set up a Special Investigation Team amid massive outrage.

In May, the Army had concluded its inquiry stating that the killings of civilians was “a case of mistaken identity and error of judgement”.

The Mon killings had led to protests in Nagaland and renewed demands to repeal the Armed Forces (Special Powers) Act. The law gives Army personnel in “disturbed areas” sweeping powers to search, arrest, and open fire if they deem it necessary for “the maintenance of public order”.

On April 1, the law was revoked in 23 districts of Assam and 15 police stations jurisdictions in Manipur and Nagaland. On April 28, Prime Minister Narendra Modi had said the Centre was making efforts to completely remove the Act from the North East.